Wind turbines, such as the conventional windmill, are used in the generation of power. In various geographic regions of the world, these machines experience a very wide range of wind conditions, some of which may destroy the propeller system. FIG. 1 illustrates a prior art wind turbine 10 and a support base 20 having a propeller 11 with blades 42 mounted on a hub 30 for rotating about a hub axle 35 that connects to a generator 40. The blades are canted in a direction that produces a maximum torque and rotational velocity when the wind velocity is perpendicular to the propeller 11. Typically this angle is 45 degrees. High wind speeds can cause damage to wind turbine blades 42. To reduce the likelihood of damage some wind turbines have relatively small diameter blades and an off-set shaft with angled tail mounting that aims (furls) the propeller in a direction parallel to sustained heavy cross-winds. While such configuration has proven effective to combat sustained heavy winds, strong cross wind gusts often destroy these structures.
Power generation wind turbines use low surface area propellers. These devices, however, exhibit very poor performance during low wind conditions. Therefore, locations where winds are reliably sustained, such as upon a hill-top for example, become necessary locations for these structures to produce any power most of the time. The power generation wind turbines typically feature three blades with small areas. However, at low wind speed little or no power is produced. In some prior art systems a variable blade pitch accommodates high-speed operation, but does not work well at low speed where traction on the air medium is most needed. Conventionally, a wind turbine will have a mechanical means to cause the entire rotor to turn to a position where the plane of rotation of the blades is parallel to the direction of the wind when the wind velocity becomes excessive. This manner of operation tends to reduce the risk of damage under high, steady wind conditions, but proves inadequate to compensate for abrupt changes in wind direction, such as during storms or other severe weather conditions. A wind turbine propeller that reliably performs under low wind conditions to produce optimum power and yet avoids destruction to the blades under high wind conditions or abrupt wind changes is desired.